Application of lean concepts and simulation analysis to improve efficiency of drainage operations maintenance crews

The City of Edmonton's Drainage Operations branch oversees the inspection, maintenance, and repair of the city's drainage network. This network covers an area of 700.6 km2 to serve the city's growing population of nearly 1 million people. The activities performed by this division consume a large amount of funding and are, therefore, receptive to improvements in productivity. The study presented in this paper was conducted to develop improved work methods and engineered productivity standards for the various drainage operations. The study focused on six crews, which accounted for over 25% of the total drainage operations budget. The six crews were divided based on their respective duties: (1) cleaning mains by low pressure flushing (LPF); (2) cleaning mains by high pressure flushing; (3) scheduled mechanical cleaning of catch basins (CBC); (4) inspecting mains by televising; (5) commercial establishment investigation; and (6) service-line rodding and televising. The study utilized the concept of work simplification and focused on two crew activities-LPF and CBC work tasks-to improve crew work methods, to develop an established work standard, and to verify the proposed improvements based on the simulation model's output. These activities are described in greater detail in two case studies. The work measurement concept was implemented to develop engineered productivity standards for the remaining crews in order to improve their productivity as well. This paper describes the application of an industrial engineering philosophy of work measurement-lean production theory-and the technique of simulation analysis to capture current work methods, generate and test alternative methods, and develop new productivity standards for drainage maintenance operations crews.